Future generations of flexible, transparent electronics will require the use of polymer based thin-film transistors (TFTs) exhibiting high carrier mobility. The problem of enhancing TFT characteristics is addressed in this report. We investigate the nanoscale, self-assembled monolayer (SAM) influence on organic-based thin film transistors (OTFT) at the interface between semiconducting polymer and both the source/drain metal contacts and the insulator. Capacitance-voltage (C-V) characteristics help to elucidate the role of SAMs in the OTFT structure and the charge injection mechanism. Positive trends and parasitic effects are also addressed in characterization.